create snapcraft.yaml  for snapcraft.io

* add a simple test for is_push so that every small utility has a corresponding unit test

* split evm/factory.rs into two files as the TODO suggests

* style fixes according to review comments

* Add dev chain to isTest

* Fix signer

* Fix no condfition transactions

* Fix case : old parity

* Fix propTypes.

* EIP-210

* comment

fixes typo

* Fixed --datadir

* Removed evmbin lib

* helpers-1

* helpers2-impls1

* small adjustments1

* cleanup-2

* small changes

* helper-impl-cleanup-finished

* test-update

* merge fix

* merge fix

* merge fix2

* fix tests

* fix tests2

* fix tests3

https://github.com/paritytech/parity/issues/4937